View single post by vnavaret
 Posted: 06-29-2025 03:09 am
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vnavaret



Joined: 04-07-2022
Location: Oregon USA
Posts: 108
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 You can use a socket on the crank pulley and perhaps a breaker bar after putting the gearbox  in neutral. Instead of a socket, you can put the car in fourth gear and push the car while watching the crank pulley - I find this method the easiest as long as there is room to move the car.

Get a copy of the shop manual for the procedure. If you are going to do your own maintenance, and it sounds like you are,  you need the shop manual. Martin Robey sells the manual, as does the Jensen owners club. You can also get used copies on eBay.

When positioning the cam sprockets, you need to replace the cam belt if there are any cracks or damaged teeth on the belt. Make sure that you put the correct sprocket on the correct cam - early sprockets are marked IN or EX for the intake or exhaust, later motors used interchangeable sprockets with two sets of marks.

You must rotate the crank to position the number one cylinder at top dead center, then rotate the cams such that the timing marks point at each other. For early engines, the marks will be IN and EX. For later engines there will be two sets of marks - 110 and 115 each mark will have the letters IN or EX associated the number. For the intake cam, you use the number designated IN, and on the exhaust the number associated with the letters EX. 

You will need to decide whether to use the 110 marks, or the 115 marks. The 110 marks will give you more power, a slightly rougher idle, increased emissions and lower fuel economy. The 115 marks will give a smoother idle, broader power band, better economy and emissions, and slightly lower peak power.

You will note that later pulleys have markings on both sides of the sprockets. Because of this, you can even mix and match the timing numbers of the sprockets, but whatever number you use, you must end up with IN on the intake cam aligned with EX on the exhaust cam.

The ignition sprocket should have the "F" mark pointing at the center of the crankshaft sprocket.

Note that the marks on the sprockets were changing over time to meet the changing emissions regulations. There were some sprockets with 100 and 110 timing marks. If you have these sprockets, you are supposed to set the 100IN mark aligned to the 110EX mark (North America only).

Vance

Last edited on 06-29-2025 03:14 am by vnavaret